COLUMBIA, S.C.  — For the past two days, a sign on the cafeteria door at Hammond School read, “Jews and dogs not allowed.” The sign was part of the 6th grade’s simulation of 1930s Germany in which students were divided into two groups _ Nazis and Jews.

The students portraying Nazis spent a day as a privileged class, sitting in front rows, serving as teachers’ pets and being told they were smart.

Meanwhile, the students who portrayed Jews ate in silence in the hallways, sat on the floor in the backs of classrooms and wore stars pinned to their shirts, said Karen Shull, the 6th-grade English teacher who created the simulation.

Such simulations are performed in schools across the country as a way of teaching that prejudice can be casual and easy to adopt. While Hammond’s program is highly structured and appears to generate little criticism, education experts say similar simulations have gotten out of hand and been harmful to students.

They urge schools to proceed with caution when planning them.

The simulation has brought some Hammond students to tears as they grow frustrated with their second-class status, Shull said.

After spending Wednesday in their assigned roles, the students switched places Thursday, allowing everyone a chance to experience both sides of the history lesson, Shull said.

“The students in the first group were pretty downtrodden,” she said.

“Then their talk changed. It’s very interesting to see how quickly they switch roles. I’ve had several say, ‘I’m so glad I’m German today.'”

Students kept journals about their roles and how they felt. All 68 students were assigned an essay chronicling their reactions to the simulation. And, a Holocaust survivor and author from New York was coming to speak to middle and upper school students.

The whole experience coincided with Holocaust Remembrance Day on Jan. 27 and was designed around the book “Daniel’s Story” by Carol Matas, Shull said.

These forms of academic simulations are fairly common, but education experts warn they must be designed and monitored with caution. The danger comes when students become too aggressive or students who already have emotional problems feel bullied, said Nathan Carnes, an associate professor at the University of South Carolina’s College of Education.

“Middle school can be an awkward period of time,” Carnes said. “One must be careful and very scrupulous about these learning experiences. On the other hand, what we know in education is the highest form of learning for students is through experience.”

The Holocaust simulation has been part of the 6th grade curriculum for four years at Hammond, a private school in Columbia, S.C., where the annual middle school tuition is $13,720. Parents receive an information paper about the program and sign a permission slip for their children to participate, Shull said.

So far, no one has opted out, although a few parents have expressed concerns about it.

Shull said one Jewish family reluctantly allowed their daughter to participate but were pleased enough that they didn’t hesitate to sign their son’s permission slip two years later, she said.

The school’s student body is 14 percent minority students, according to its website.

Teachers in all courses prepare lesson plans around the theme, and they spend a lot of time talking to students about what really happened during Nazi Germany in the 1930s and the build-up to World War II. The students face questions such as how one person can change the world and what it means to have empathy for someone else, Shull said.

“It really takes a lot of front-end work to prepare for the mindset of standing in other people’s shoes and seeing what it really feels like,” Shull said.

Laura Riley, a middle school geography teacher at Hammond, said the students always are in a controlled environment during the two days of simulation, so students don’t have down time to pick on each other.

Students are separated at lunch and in locker rooms, which serves two purposes, Riley said.

“Part of it is we want them to experience the inequality and part of it is we want to keep them safe,” she said.

Educational simulations came to life in 1967 when Jane Elliott, an Iowa elementary school teacher, created the famous blue-eyed/brown-eyed experiment in which students were separated based on eye color and one set was told its members were more intelligent.

She discovered that the blue-eyed children who were told they were special began acting as if they were superior to the brown-eyed students.

Since then, the simulation has been conducted in various role-playing formats such as re-enacting the slave trade or the Underground Railroad, said Maureen Costello, director of the Southern Poverty Law Center’s Teaching Tolerance program.

The Alabama-based organization uses its tolerance program to help kindergarten through 12th-grade teachers incorporate equality and justice into their classrooms.

“A lot of educators are wary of this kind of immersion because it’s not really authentic,” Costello said. “And if you’re not careful, you can do a lot of damage.”

Costello said she was not familiar with Hammond’s program. After listening to a description of it, Costello said it sounded “well thought out.”

She encourages schools that use similar immersion programs to take time to incorporate modern discrimination examples, such as today’s U.S. attitudes toward Muslims and Hispanics or even girls’ sports.

“Are they equipped to recognize some of today’s injustices?” she said. “Tie it to contemporary issues.”

Riley, who now teaches 8th grade geography at Hammond, said the school broadens the lesson by looking at discrimination on a global scale, such as genocide in Darfur. And the teachers use it to teach basic, school-day thoughtfulness such as including others at a lunch table.

“It opens the door for conversations later for the cool girl who has always been treated like a queen and now she’s had a day where she’s been mistreated and had to walk a mile in someone else’s shoes,” she said.

• Noelle Phillips